Sudsing profile is important for a cleaning composition, particularly laundry detergent, where the appropriate volume and speed of suds formation, retention and dissolution in the wash and rinse cycles are considered key benchmarks of performance by the consumers. For laundry detergents, while a suds profile is important for machine washing process, it is even more important in a typical hand-washing process as the consumer would see changes in the suds level in the wash and rinse cycles. Typically, consumers, particularly hand-washing consumers, desire laundry detergent that dissolves in the wash liquor to give voluminous suds during the wash cycle to signify sufficient performance. The suds are then carried over to the rinse solution and require additional time, water and labour to thoroughly rinse from the laundered fabric.
However, reducing the suds level overall is not a viable option because when the consumer sees lower suds or nil suds during the washing cycle, it causes the consumer to believe that the laundry detergent is not as active. In addition, the current market demands are for laundry detergents with improved environmental sustainability (e.g., less water consumption) without negatively impacting cleaning performance or the perception of cleaning performance (i.e., appearance of suds on fabric or in the rinse solution). This, of course, reinforces the preference for laundry detergents having improved foam control composition for faster suds dissolution during the rinse cycle so as to reduce extra rinse cycles needed to remove the suds from the cleaned fabrics/rinse solution. Thus, there is a need for a cleaning composition having a sudsing profile where there is strong level of suds volume during the washing cycle, and yet quickly collapses in the rinsing solution for substantially reduced or nil suds for cost savings and environmental conservation purposes. This is known as the “single rinse” concept.
One solution has been to add a de-foamer product during the rinse cycles, but this option is cost prohibitive for most hand-washing consumers. Additionally, the prior art discloses laundry detergent compositions with various foam control agents in an attempt to address this problem. For example, PCT Publication No. WO2011/107397 (Unilever) discloses a laundry detergent composition comprising a delayed-release amino-silicone based antifoam agent to act in the rinsing cycle to highly reduce or eliminate suds, preferably after two rinse cycles. Here, the antifoam agent is absorbed onto a carrier filler. EP Publication No. EP0685250A1 (Dow Corning) discloses a foam control composition for use in laundry detergents that inhibits the formation of new suds during the post-wash rinsing cycles, but which does not appear to quicken the elimination of already existing suds carried over from the wash cycle.
Accordingly, there is a need for a cleaning composition, preferably a laundry detergent, which permits strong suds formation during the washing while eliminating the suds quickly during the rinse cycle(s), preferably across a range of consumer wash habits and fabric/material surfaces being washed, so that a single rinse cycle might be sufficient to remove the suds. There is also a need for a cleaning composition, preferably a laundry detergent, having substantially improved benefits, such as for example, improved rinse clarity of a laundry liquor, positive effect on skin by the consumer using the laundry detergent, or improved fabric feel after the items have been laundered using the laundry detergent.
It is desirable that the cleaning compositions are preferably relevant to an anionic detersive surfactant system, such as for example, alkyl benzene sulphonic acid or salt thereof, alkyl ethoxylated sulphate, or a mixture thereof.